Dog and cat diarrhoea with blood is usually due to damage to the gastrointestinal mucosa caused by bacteria, viruses, pancreatitis or mechanical damage from foreign bodies. A dark brown colour is usually bleeding from the small intestine; a bright red colour is often bleeding from the large intestine. Observe for vomiting and stool patterns, monitor temperature and protect the gastrointestinal mucosa to avoid enterotoxaemia and septicaemia.
